Am 07.04.06, 22:39 +0200 schrieb Pavel Kanzelsberger: > Hi, > > I'm new to this list... first of all, thanks for this great CMS engine, > I'm using it in my application (Pixel image editor). > > Right now I'm playing with Pantone colors, they're defined as > double-floats (64-bit) Lab and I would like to convert them to 8-bit Lab > (type_Lab_8)... simple rounding and clipping doesn't work well, maybe I > need to multiply those values with some factor but I can't find the > right one... any hints please? I see that L=0..255,a/b=-128..127 :)
*L 0..100 > Another thing is that I have HDR images with single float (32-bit) per > channel, is there any way to define such type for lcms transform or > should I convert it to 16-bit RGB before I want to convert to let's say > Lab? I'm wondering if I'm not loosing any precision... as HDR values are > in range 0.0 ... 1.0, conversion to 16-bit RGB is then just multiply by > 65535, but in HDR there are higher values than 1.0 possible, for > example, paper=1.0, sun=549312.0 :) Lcms is not useful for HDR conversions. The data will be clipped. Nethertheless you can do the display transformation with lcms after tonemapping. > Thanks for any answers! > > regards, > -- > Pavel Kanzelsberger > http://www.kanzelsberger.com > E-Mail: [EMAIL PROTECTED], ICQ: 209 906 33 > Jabber: [EMAIL PROTECTED] regards Kai-Uwe Behrmann + development for color management + imaging / panoramas + email: [EMAIL PROTECTED] + http://www.behrmann.name ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
